CN108458987A - A kind of THz wave computer-aided tomography imaging device and method - Google Patents
A kind of THz wave computer-aided tomography imaging device and method Download PDFInfo
- Publication number
- CN108458987A CN108458987A CN201810568221.7A CN201810568221A CN108458987A CN 108458987 A CN108458987 A CN 108458987A CN 201810568221 A CN201810568221 A CN 201810568221A CN 108458987 A CN108458987 A CN 108458987A
- Authority
- CN
- China
- Prior art keywords
- thz wave
- terahertz
- liquid tank
- thz
- imaging device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003384 imaging method Methods 0.000 title claims abstract description 49
- 238000003325 tomography Methods 0.000 title claims abstract description 43
- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000007788 liquid Substances 0.000 claims abstract description 65
- 239000012530 fluid Substances 0.000 claims abstract description 14
- 238000010521 absorption reaction Methods 0.000 claims abstract description 9
- 230000008569 process Effects 0.000 claims abstract description 5
- 238000013519 translation Methods 0.000 claims description 23
- 238000005259 measurement Methods 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 6
- 229920001903 high density polyethylene Polymers 0.000 claims description 5
- 239000004700 high-density polyethylene Substances 0.000 claims description 5
- 239000005662 Paraffin oil Substances 0.000 claims description 4
- 238000012544 monitoring process Methods 0.000 claims description 3
- 238000007493 shaping process Methods 0.000 claims description 3
- 238000004587 chromatography analysis Methods 0.000 claims description 2
- 238000007747 plating Methods 0.000 claims 1
- 238000012545 processing Methods 0.000 abstract description 4
- 238000001914 filtration Methods 0.000 abstract 1
- 238000005516 engineering process Methods 0.000 description 8
- 238000001514 detection method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000005855 radiation Effects 0.000 description 5
- 238000007689 inspection Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- TVEXGJYMHHTVKP-UHFFFAOYSA-N 6-oxabicyclo[3.2.1]oct-3-en-7-one Chemical compound C1C2C(=O)OC1C=CC2 TVEXGJYMHHTVKP-UHFFFAOYSA-N 0.000 description 1
- 206010006187 Breast cancer Diseases 0.000 description 1
- 208000026310 Breast neoplasm Diseases 0.000 description 1
- 201000009030 Carcinoma Diseases 0.000 description 1
- 208000032612 Glial tumor Diseases 0.000 description 1
- 206010018338 Glioma Diseases 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 230000006854 communication Effects 0.000 description 1
- 238000002591 computed tomography Methods 0.000 description 1
- 238000013480 data collection Methods 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000023077 detection of light stimulus Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- VIKNJXKGJWUCNN-XGXHKTLJSA-N norethisterone Chemical compound O=C1CC[C@@H]2[C@H]3CC[C@](C)([C@](CC4)(O)C#C)[C@@H]4[C@@H]3CCC2=C1 VIKNJXKGJWUCNN-XGXHKTLJSA-N 0.000 description 1
- -1 polytetrafluoroethylene Polymers 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 230000011514 reflex Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 210000001519 tissue Anatomy 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3581—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation
Abstract
The invention discloses a kind of THz wave computer-aided tomography imaging device and methods, including：THz wave continuous scanning imaging system based on index-matching fluid and data processing algorithm.Index-matching fluid is filled in liquid tank, and sample is immersed in liquid tank and is scanned when imaging, can be to avoid the beam deviation in scanning process since two light pass surfaces of liquid tank are perpendicular to the thz beam of focusing；Data processing algorithm uses the internal information of filter back-projection algorithm reconstruction sample for filtering out the absorption of noise and liquid to THz wave caused by the fluctuation of terahertz emission source power.The liquid tank that the present invention passes through index-matching fluid built in introducing, efficiently solve thz beam refraction and reflection problems caused by sample refractive index is higher, secondly, by the decaying of liquid during analog scanning and data for projection is modified, liquid absorption influence on RT is eliminated, realizes and the T-ray tomography of high refractive index sample is imaged.
Description
Technical field
The present invention relates to THz wave technical field of imaging more particularly to a kind of liquid using built-in index-matching fluid
Slot realizes the device and method for the THz wave computer-aided tomography imaging being imaged to high refractive index sample.
Background technology
Terahertz (Terahertz, abbreviation THz, 1THz=1012Hz) wave band refers to frequency from 100GHz to 10THz, accordingly
Wavelength from 3 millimeters to 30 micron, the comparatively wide electromagnetic spectrum region of spectral range between millimeter wave and infrared light.Due to
The frequency range is frequency range of the macroelectronics to microcosmic photonic propulsion transition, has many unique properties, such as many large biological molecules
Vibration and rotational energy level, and the phonon of many condensed state systems and other yuan of excitation be all located at terahertz wave band, therefore, can
To carry out fingerprint recognition to substance by characteristic resonances and absorption；The photon energy (milli electron-volt) of THz wave is low, generally
Biological tissue and cell will not be damaged, organism can be carried out non-destructive testing；THz wave to many visible and
Infrared band opaque nonmetallic, non-polar material have stronger penetration capacity, can carry out transmission imaging.Therefore, terahertz
Hereby technology all has broad application prospects in physics, life science, information technology and science and techniques of defence etc..Terahertz
Wave imaging is one of most important application of Terahertz science and technology, transmission-type has currently had been developed, reflective, decaying is all-trans
It penetrates, Active Imagings technology and the imaging and passive imaging technology such as Near-Field Radar Imaging, and in nondestructive inspection, explosive detection, historical relic research, peace
Inspection, drug detection etc., especially detection application of the biomedical aspect such as to cutaneum carcinoma, glioma and breast cancer
Aspect achieves huge progress.But traditional THz wave two-dimensional imaging technique can only reflect surface or the entirety of sample
Information cannot be satisfied the demand of internal information observation.
3 Dimension Image Technique is one of the effective means for obtaining sample interior information, since proposition, in microwave, visible
Light infrared is verified with fields such as THz waves.Compared with the electromagnetic spectrum of other different frequency ranges, x-ray photon energy
Amount is higher, has ionising radiation to organism；Infrared light is relatively low to the penetration depth of sample；Although millimeter wave transmitance is high, its
Resolution ratio is limited by long wavelength；The penetrability of THz wave is good, and resolution ratio can meet actual requirement, therefore utilize Terahertz
Wave, which carries out three-dimensional imaging, better effect.It is calculated currently, more mature THz wave 3 Dimension Image Technique is THz wave
Machine auxiliary chromatography (Computed Tomography, CT), can be regarded as extension of the X ray CT on electromagnetic wave band.
Currently, T-ray tomography imaging system and its algorithm for reconstructing are mostly based on x-ray ct technology, however THz wave is in sample
Communication process in product and X-ray simultaneously differ, and X-ray on surface or internal all along linear transmission, does not almost have either
There are reflection and refraction.But air and sample have larger difference in the refractive index of terahertz wave band, THz wave is in sample table
The refraction in face and reflex are very serious, and when it is with different incidence angles incidence, reflectivity is different and anaclastic
Deflection is also different, this proposes higher requirement to the reconstruction of image and the detection of light beam.For these reasons, in T-ray tomography
Early-stage study in find, when being imaged to the complicated and higher sample of refractive index (such as turkey bone, polytetrafluoroethylene (PTFE)), internal junction
Structure can not be shown, this is caused by the strong reflection on boundary and refraction.It can be seen that in view of THz wave itself
Beam characteristics, when to object absorption coefficient and refractive index reconstruction, the limitation of terahertz wave detector itself and the refraction of sample,
The problems such as reflection loss, can largely influence image quality.It is whole in order to enable detector to be collected into as much as possible
The light beam of diverging can be focused on detector detection aperture model by transmitted light beam using face mirror or lens focus transmitted light beam is thrown
In enclosing, but this can not solve the problems, such as that light beam deviation causes.Due to refraction and the presence of reflection problems, at present T-ray tomography
It mostly uses low-refraction sample greatly to be studied, significantly limits its development and application.
Invention content
The present invention provides a kind of THz wave computer-aided tomography imaging device and methods, and the present invention overcomes light beams
The problem of refraction and reflection cause realizes the THz wave computer-aided tomography imaging to high refractive index sample, refers to down
Text description：
A kind of THz wave computer-aided tomography imaging device, described device include：
Diaphragm is arranged before condenser lens, and shaping is carried out for limited spot size and to light beam；
THz wave is divided into two bundles by Terahertz beam splitter, light beam as signal light, by after Imaged samples by first
Terahertz wave detector detects, and another beam is detected by the second terahertz wave detector, the power for monitoring terahertz emission source
Fluctuation improves signal-to-noise ratio with this；
Electric control rotating platform is fixed in the first automatically controlled one-dimensional translation stage, and the first automatically controlled one-dimensional translation stage is fixed on the second electricity
It controls in one-dimensional translation stage, electric control rotating platform connects Imaged samples, so that it is dipped vertically into liquid tank from top to bottom, in liquid tank
Full of index-matching fluid, Imaged samples is made to receive scanning in liquid environment；
Computer control system controls program by continuous scanning and controls two automatically controlled one-dimensional translation stages and automatically controlled rotation
Platform carries out continuous scanning, while realizing and being adopted to the first terahertz wave detector and the second terahertz wave detector measurement data
Collection, and measurement data is handled, obtain terahertz tomographic image.
When specific implementation, the liquid tank is fixed in scanning process, and the center of liquid tank is poly- positioned at THz wave
Jiao Guangbanchu, two light pass surfaces of liquid tank are perpendicular to light beam.
Wherein, the focal length of the condenser lens is determined according to the required Rayleigh range of Imaged samples.Preferably, described poly-
The Rayleigh range of the focus on light beam of focus lens should be close to the radius of Imaged samples.
Preferably, two light pass surfaces of the liquid tank are made of white high-density polyethylene material, thickness 1mm.
Further, liquid is paraffin oil.
When specific implementation, described device further includes：Gold-plated off-axis throwing face mirror, for focusing through the Terahertz after sample
Wave makes the light beam of diverging focus in the detection aperture of detector；It is additionally operable to converge the thz beam of different deviation angles, drop
The influence of low refraction.
Preferably, the aperture of the gold-plated off-axis throwing face mirror is 50.8mm, focal length 50.8mm.
Further, the THz wave frequency range of the terahertz emission source transmitting is 0.1THz-10THz.
A kind of THz wave computer-aided tomography imaging method, the described method comprises the following steps：
1) by the data that the first terahertz wave detector measures divided by the data that the second terahertz wave detector measures,
Influence caused by for reducing terahertz emission strength fluctuation, while significantly Removing Random No and ambient noise；
2) according to the shape of Imaged samples and liquid to the absorption coefficient of THz wave, liquid during analog scanning
Decay and data for projection is modified；
3) revised data for projection is handled using filter back-projection algorithm, obtains one section of Imaged samples
Tomography figure；
4) three-dimensional modeling is carried out to multiple longitudinal sections, completes, to the three-dimensional tomography of Imaged samples, to obtain Terahertz
Tomography figure.
The advantageous effect of technical solution provided by the invention is：
1, the entire light path in the present invention is only with the gold-plated off-axis throwing face mirror focus on light beam of a lens and one, light
Road is simple, and stability is good, reduces complexity, and since light path is compact, can further decrease the shadow of light beam deviation generation
It rings；
2, the present invention using two same model detectors is carried out at the same time acquisition to radiation source reference light and signal light, can be with
Influence of the fluctuation to imaging data of radiation source is effectively reduced, imaging signal-to-noise ratio is improved；
3, the present invention places the light pass surface of the liquid tank of built-in index-matching fluid perpendicular to thz beam, and uses
Index matching liquid submerges sample so that during sample is scanned in lateral x-axis and rotated in x/y plane, light beam begins
It will not reflect eventually；
4, of the invention since incidence angle is always zero, intensity of reflected light is also constant in scanning process, further obviates
Noise caused by intensity of reflected light changes with scan position；
5, method proposed by the present invention, which can efficiently solve, makes in T-ray tomography imaging since sample refractive index is higher
At refraction to light beam and reflection problems, realize the imaging to high refractive index sample；
6, the present invention can promote the research and development of T-ray tomography imaging technique, and greatly improve T-ray tomography
The application prospect of technology so that it has wide application value in industrial non-destructive field of detecting.
Description of the drawings
Fig. 1 is the structural schematic diagram of Terahertz computer-aided tomography imaging device；
Fig. 2 is the flow chart of Terahertz computer-aided tomography imaging method；
Fig. 3 is the schematic diagram of Imaged samples pictorial diagram (a) and T-ray tomography imaging results (b).
In attached drawing, what each component indicated is listed as follows：
1：Terahertz emission source； 2：Terahertz beam splitter；
3：Diaphragm； 4：Condenser lens；
5：Liquid tank； 6：Index-matching fluid；
7：Imaged samples； 8：Electric control rotating platform；
9：First automatically controlled one-dimensional translation stage； 10：Second automatically controlled one-dimensional translation stage；
11：Gold-plated off-axis throwing face mirror； 12：First terahertz wave detector；
13：Second terahertz wave detector； 14：Computer control system.
Wherein, the first terahertz wave detector 12, the model of the second terahertz wave detector 13 are identical.First is automatically controlled one-dimensional
Translation stage 9 is moved in x-axis direction, and electric control rotating platform 8 rotates in x/y plane, and the second automatically controlled one-dimensional translation stage 10 is in z-axis side
To movement.The front-back (shadow region in Fig. 1) of liquid tank 5 is light pass surface, and the material of light pass surface is that white high density is poly-
Ethylene (HDPE).
Specific implementation mode
To make the object, technical solutions and advantages of the present invention clearer, embodiment of the present invention is made below further
It is described in detail on ground.
Embodiment 1
A kind of THz wave computer-aided tomography imaging device, referring to Fig. 1, which includes：Terahertz emission source 1,
Terahertz beam splitter 2, diaphragm 3, condenser lens 4, liquid tank 5, index-matching fluid 6, electric control rotating platform 8, first automatically controlled one
Tie up translation stage 9, the second automatically controlled one-dimensional translation stage 10, gold-plated off axis paraboloidal mirror 11, the first terahertz detector 12, the second terahertz
Hereby detector 13 and computer control system 14.
Wherein, the THz wave frequency range in terahertz emission source 1, transmitting is 0.1THz-10THz.Diaphragm 3 is placed
Before condenser lens 4, shaping is carried out for limited spot size and to light beam (i.e. THz wave), to improve terahertz after focusing
The hereby Rayleigh range and beam quality of light beam.
Condenser lens 4 has high transmittance in terahertz wave band, and focal length is according to 7 required Rayleigh of actual imaging sample
Length determines, when specific implementation, the embodiment of the present invention is not restricted this.
The thz beam of terahertz emission source output has Gaussian beam characteristic, and spot radius is in beam direction (y-axis
Direction) meet：
Wherein, ω0For focus spot radius, z is hot spot at a distance from focus, zRFor Rayleigh range, can be expressed as：
Wherein, λ is the wavelength of THz wave.
The size of Gaussian beam hot spot is within the scope of Rayleigh range close to the size of its focal beam spot.In order to carry as much as possible
High imaging resolution, it is preferable that the Rayleigh range of 4 focus on light beam of condenser lens should be close to the radius of Imaged samples 7.
THz wave is divided into two bundles by Terahertz beam splitter 2, light beam as signal light, by after Imaged samples 7 by
One terahertz wave detector 12 detects, and another beam is detected by the second terahertz wave detector 13, for monitoring terahertz emission source
Power swing signal-to-noise ratio is improved with this.
Liquid tank 5 is fixed in scanning process, and the center of liquid tank 5 is located at THz wave focal beam spot, liquid
Two light pass surfaces of slot 5 are full of index matching liquid in light beam (i.e. THz wave), liquid tank 5, make Imaged samples 7
Receive scanning in liquid environment, so as to avoid because of light beam (i.e. THz wave) refraction and reflection cause the problem of.
When specific implementation, the first automatically controlled one-dimensional translation stage 9 is fixed in the second automatically controlled one-dimensional translation stage 10, automatically controlled rotary flat
Platform 8 is fixed in the first automatically controlled one-dimensional translation stage 9, and electric control rotating platform 8 connects Imaged samples 7, makes Imaged samples 7 from top to bottom
It is dipped vertically into liquid tank 5, electric control rotating platform 8 drives Imaged samples 7 to realize rotation in liquid tank 5.
Computer control system 14 controls program by continuous scanning and controls two automatically controlled one-dimensional translation stages 9,10 and electricity
It controls rotating platform 8 and carries out continuous scanning, while realizing to the first terahertz wave detector 12 and the second terahertz wave detector 13
The acquisition of measurement data.
Embodiment 2
A kind of THz wave computer-aided tomography imaging method, referring to Fig. 2, which includes following mistake
Journey：
1) data that the first terahertz wave detector 12 measures divided by the second terahertz wave detector 13 are measured
Data；
By the processing of the step, influence caused by reduce terahertz emission strength fluctuation, while can significantly eliminate
Random noise and ambient noise.
2) according to the shape of Imaged samples 7 and liquid to the absorption coefficient of THz wave, liquid during analog scanning
Decaying and data for projection is modified；
3) revised data for projection is handled using filter back-projection algorithm, obtains 7 one sections of Imaged samples
Tomography figure；
4) three-dimensional modeling is carried out to multiple longitudinal sections, completes, to the three-dimensional tomography of Imaged samples 7, to obtain Terahertz
Tomography figure.
Preferably, two light pass surfaces of liquid tank 5 are made of white high density polyethylene (HDPE) (HDPE) material, and thickness is
1mm makes light pass surface not cause larger decaying to THz wave, and will not be deformed when hydraulically full in liquid tank 5.
Preferably, index-matching fluid 6 uses paraffin oil, this liquid to have very high transmitance in terahertz wave band,
And it is close in the refractive index of refractive index and the most of samples of terahertz wave band, make thz beam liquid at decent
Deviation will not occur for the contact surface of product 7.
Preferably, the aperture of gold-plated off-axis throwing face mirror 11 is 50.8mm, focal length 50.8mm.
Embodiment 3
The scheme in embodiment 1 is described in detail with reference to Fig. 1, it is described below：
Referring to Fig. 1, the THz wave computer-aided tomography imaging device in the present embodiment, including：Generate THz wave
Radiation source 1, THz wave converges at the center of liquid tank 5 after Terahertz beam splitter 2, diaphragm 3 and condenser lens 4.At
Decent product 7 are immersed in liquid tank 5 and are connect with electric control rotating platform 8, and index-matching fluid 6 injects liquid tank 5 and submergence imaging
Sample 7 realizes that Imaged samples 7 receive in liquid under the drive of automatically controlled one-dimensional translation stage 9,10 and electric control rotating platform 8
Scanning.
First terahertz wave detector 12 and the second terahertz wave detector 13 receive signal light and reference light respectively.It calculates
Machine control system 14 by continuous scanning control program control two automatically controlled one-dimensional translation stages 9,10 and electric control rotating platform 8 into
Row continuous scanning, while realizing the acquisition to the first terahertz detector 12 and the second terahertz detector 13 to measurement data,
And initial data is handled using algorithm.
When specific implementation, two light pass surfaces of liquid tank 5 are made of white high density polyethylene (HDPE) (HDPE) material, thickness
For 1mm, light pass surface is set not cause larger decaying to THz wave, and will not become when hydraulically full in liquid tank 5
Shape.
Further, aforesaid liquid is preferably paraffin oil, and this liquid has very high transmitance in terahertz wave band, and
And it is close in the refractive index of terahertz wave band and the refractive index of most of sample, makes thz beam connecing in liquid and sample
Contacting surface will not reflect.
Embodiment 4
With reference to Fig. 1 and Fig. 2, the scheme in embodiment 2 is described in detail, it is described below：
The device makes Imaged samples 7 be scanned in liquid environment by the liquid tank 5 of index-matching fluid built in introducing 6,
Eliminate light beam refraction and reflection the problem of causing.
First, Imaged samples 7 carry out projection scanning along the x-axis direction under the drive of the first automatically controlled one-dimensional translation stage 9, automatically controlled
Rotating translation stage 8 drives Imaged samples 7 to be rotated in x/y plane, a projection scanning is carried out every 3 °, corotating projects 60 times, complete
At the scanning of a section.
Since the light pass surface of liquid tank 5 is perpendicular to thz beam, thz beam will not when through liquid tank 5
It reflects.Also, Imaged samples 7 and index-matching fluid 6 are in the refractive index close of terahertz wave band, therefore, THz wave
In incident and outgoing sample, will not reflect substantially.During scanning, since liquid tank 5 is fixed, only
Imaged samples 7 in rotation sweep, therefore can to avoid due to Imaged samples 7 rotate caused by THz wave incidence angle change
Change.
Computer control system is handled raw measurement data using data processing algorithm：
1) by the data that the first terahertz detector 12 measures divided by the data that the second terahertz detector 13 measures,
Can reduce influences caused by terahertz radiation strength fluctuation, while can significantly Removing Random No and ambient noise；
2) according to the shape of Imaged samples 7 and liquid to the absorption coefficient of THz wave, liquid during analog scanning
Decaying and data for projection is modified, eliminate liquid absorption influence on RT；
3) revised data for projection is handled using filter back-projection algorithm, obtain the CT of one section of sample at
As figure.
Finally, Imaged samples 7 translate along the z-axis direction under the drive of the second automatically controlled one-dimensional translation stage 10, often move one
Step-length just carries out the scanning imagery of a section.After the end of scan, three-dimensional modeling is carried out to multiple longitudinal sections, is completed to imaging
The three-dimensional tomography of sample 7 realizes the detection to 7 internal flaw of Imaged samples or foreign matter.
Wherein, above-mentioned that revised data for projection is handled using filter back-projection algorithm, it obtains one, sample and cuts
The step of CT images in face, is known to those skilled in the art, and the embodiment of the present invention does not repeat this.
Embodiment 5
Feasibility verification is carried out to the device and method in embodiment 1-4 with reference to Fig. 3, it is described below：
This experiment carries out T-ray tomography imaging to the white high density polyethylene (HDPE) cylinder of internal existing defects, as shown in Figure 3.
Wherein Fig. 3 (a) is Imaged samples pictorial diagram, and the circular flaw of specially diameter 25mm, the cylinder of high 10mm, inside are a diameter of
Sample center 6mm is deviateed in 8mm, defect center.Fig. 3 (b) is shown carries out T-ray tomography imaging using the present invention to the sample
Experimental result.In experiment, transversal scanning step-length is 500 μm, and rotary step is 3 °, and image slices vegetarian refreshments number is 70 × 70.From Fig. 3
(b) as can be seen that the shape of sample and the shape of internal flaw and position can correctly be shown in.Pass through above-mentioned reality
It tests, can directly verify the feasibility of device and method in the present invention.
It is calculated it is an advantage of the current invention that being handled by the liquid tank 5 and follow-up data of index-matching fluid built in introducing 6
Method, may be implemented to the imaging of the T-ray tomography of high refractive index sample, efficiently solve currently since light beam refraction leads to not pair
High refractive index sample carries out the problem of T-ray tomography imaging.Whole system is simple and compact for structure, can be widely applied to scientific research, historical relic
The fields such as nondestructive inspection, industrial stokehold.
To the model of each device in addition to doing specified otherwise, the model of other devices is not limited the embodiment of the present invention,
As long as the device of above-mentioned function can be completed.
It will be appreciated by those skilled in the art that attached drawing is the schematic diagram of a preferred embodiment, the embodiments of the present invention
Serial number is for illustration only, can not represent the quality of embodiment.
The foregoing is merely presently preferred embodiments of the present invention, is not intended to limit the invention, it is all the present invention spirit and
Within principle, any modification, equivalent replacement, improvement and so on should all be included in the protection scope of the present invention.
Claims (10)
1. a kind of THz wave computer-aided tomography imaging device, which is characterized in that described device includes：
Diaphragm is arranged before condenser lens, and shaping is carried out for limited spot size and to light beam；
THz wave is divided into two bundles by Terahertz beam splitter, light beam as signal light, by after Imaged samples by the first terahertz
Hereby wave detector detects, and another beam is detected by the second terahertz wave detector, the power swing for monitoring terahertz emission source
Signal-to-noise ratio is improved with this；
Electric control rotating platform is fixed in the first automatically controlled one-dimensional translation stage, and the first automatically controlled one-dimensional translation stage is fixed on second automatically controlled one
It ties up on translation stage, electric control rotating platform connects Imaged samples, so that it is dipped vertically into liquid tank from top to bottom, is full of in liquid tank
Index-matching fluid makes Imaged samples receive scanning in liquid environment；
Computer control system controls program by continuous scanning and controls two automatically controlled one-dimensional translation stages and electric control rotating platform
Continuous scanning is carried out, while realizing the acquisition to the first terahertz wave detector and the second terahertz wave detector measurement data,
And measurement data is handled, obtain terahertz tomographic image.
2. a kind of THz wave computer-aided tomography imaging device according to claim 1, which is characterized in that
The liquid tank is fixed in scanning process, and the center of liquid tank is located at THz wave focal beam spot, liquid tank
Two light pass surfaces perpendicular to light beam.
3. a kind of THz wave computer-aided tomography imaging device according to claim 1, which is characterized in that
The focal length of the condenser lens is determined according to the required Rayleigh range of Imaged samples.
4. a kind of THz wave computer-aided tomography imaging device according to claim 3, which is characterized in that
The Rayleigh range of the focus on light beam of the condenser lens should be close to the radius of Imaged samples.
5. a kind of THz wave computer-aided tomography imaging device according to claim 2, which is characterized in that
Two light pass surfaces of the liquid tank are made of white high-density polyethylene material, thickness 1mm.
6. a kind of THz wave computer-aided tomography imaging device according to claim 1-5 any claims,
It is characterized in that, the liquid is paraffin oil.
7. a kind of THz wave computer-aided tomography imaging device according to claim 1-5 any claims,
It is characterized in that, described device further includes：
Gold-plated off-axis throwing face mirror makes the light beam of diverging focus on the spy of detector for focusing through the THz wave after sample
In gaging hole diameter；It is additionally operable to converge the thz beam of different deviation angles, reduces the influence of refraction.
8. a kind of THz wave computer-aided tomography imaging device according to claim 7, which is characterized in that the plating
The golden off-axis aperture for throwing face mirror is 50.8mm, focal length 50.8mm.
9. a kind of THz wave computer-aided tomography imaging device according to claim 1-5 any claims,
It is characterized in that, the THz wave frequency range of the terahertz emission source transmitting is 0.1THz-10THz.
10. a kind of THz wave computer-aided tomography imaging method, which is characterized in that the described method comprises the following steps：
1) it by the data that the first terahertz wave detector measures divided by the data that the second terahertz wave detector measures, is used for
It is influenced caused by reducing terahertz emission strength fluctuation, while significantly Removing Random No and ambient noise；
2) according to the shape of Imaged samples and liquid to the absorption coefficient of THz wave, the decaying of liquid during analog scanning
And data for projection is modified；
3) revised data for projection is handled using filter back-projection algorithm, obtains the chromatography of one section of Imaged samples
Image；
4) three-dimensional modeling is carried out to multiple longitudinal sections, completes, to the three-dimensional tomography of Imaged samples, to obtain terahertz tomographic
Image.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810568221.7A CN108458987A (en) | 2018-06-05 | 2018-06-05 | A kind of THz wave computer-aided tomography imaging device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810568221.7A CN108458987A (en) | 2018-06-05 | 2018-06-05 | A kind of THz wave computer-aided tomography imaging device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108458987A true CN108458987A (en) | 2018-08-28 |
Family
ID=63216018
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810568221.7A Pending CN108458987A (en) | 2018-06-05 | 2018-06-05 | A kind of THz wave computer-aided tomography imaging device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108458987A (en) |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006084423A (en) * | 2004-09-17 | 2006-03-30 | Pentax Corp | Method and apparatus for forming transmission image |
| US20070257194A1 (en) * | 2005-03-22 | 2007-11-08 | Mueller Eric R | Terahertz heterodyne tomographic imaging system |
| CN102749341A (en) * | 2012-07-11 | 2012-10-24 | 中国科学院上海微系统与信息技术研究所 | Tomography imaging system and method based on terahertz quantum device |
| CN102980857A (en) * | 2012-11-20 | 2013-03-20 | 中国科学院光电技术研究所 | Terahertz time-domain spectroscopy system for realizing terahertz quick imaging by using frequency optical comb |
| CN103335951A (en) * | 2013-07-01 | 2013-10-02 | 成都精密光学工程研究中心 | System for measuring Terahertz reflectance of stealth material |
| WO2015014129A1 (en) * | 2013-07-29 | 2015-02-05 | 南开大学 | Thz super-resolution two-dimensional imaging method and system |
| CN104458642A (en) * | 2014-12-03 | 2015-03-25 | 天津大学 | Rapid terahertz continuous wave scanning imaging system and method |
| CN105928898A (en) * | 2016-04-15 | 2016-09-07 | 中国人民解放军第三军医大学第附属医院 | Rapidly established terahertz attenuation total reflection system based on Dove prism |
| US20170146453A1 (en) * | 2014-08-06 | 2017-05-25 | University Of Massachusetts | Single channel terahertz endoscopy |
| CN107036549A (en) * | 2016-12-30 | 2017-08-11 | 华中科技大学 | A kind of terahertz imaging device based on coherent tomographic |
| CN107631995A (en) * | 2016-07-18 | 2018-01-26 | 华中科技大学 | A kind of three-dimensional terahertz tomographic imaging system and scanning and image rebuilding method |
| CN208621514U (en) * | 2018-06-05 | 2019-03-19 | 天津大学 | A kind of THz wave computer-aided tomography imaging device |
-
2018
- 2018-06-05 CN CN201810568221.7A patent/CN108458987A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006084423A (en) * | 2004-09-17 | 2006-03-30 | Pentax Corp | Method and apparatus for forming transmission image |
| US20070257194A1 (en) * | 2005-03-22 | 2007-11-08 | Mueller Eric R | Terahertz heterodyne tomographic imaging system |
| CN102749341A (en) * | 2012-07-11 | 2012-10-24 | 中国科学院上海微系统与信息技术研究所 | Tomography imaging system and method based on terahertz quantum device |
| CN102980857A (en) * | 2012-11-20 | 2013-03-20 | 中国科学院光电技术研究所 | Terahertz time-domain spectroscopy system for realizing terahertz quick imaging by using frequency optical comb |
| CN103335951A (en) * | 2013-07-01 | 2013-10-02 | 成都精密光学工程研究中心 | System for measuring Terahertz reflectance of stealth material |
| WO2015014129A1 (en) * | 2013-07-29 | 2015-02-05 | 南开大学 | Thz super-resolution two-dimensional imaging method and system |
| US20170146453A1 (en) * | 2014-08-06 | 2017-05-25 | University Of Massachusetts | Single channel terahertz endoscopy |
| CN104458642A (en) * | 2014-12-03 | 2015-03-25 | 天津大学 | Rapid terahertz continuous wave scanning imaging system and method |
| CN105928898A (en) * | 2016-04-15 | 2016-09-07 | 中国人民解放军第三军医大学第附属医院 | Rapidly established terahertz attenuation total reflection system based on Dove prism |
| CN107631995A (en) * | 2016-07-18 | 2018-01-26 | 华中科技大学 | A kind of three-dimensional terahertz tomographic imaging system and scanning and image rebuilding method |
| CN107036549A (en) * | 2016-12-30 | 2017-08-11 | 华中科技大学 | A kind of terahertz imaging device based on coherent tomographic |
| CN208621514U (en) * | 2018-06-05 | 2019-03-19 | 天津大学 | A kind of THz wave computer-aided tomography imaging device |
Non-Patent Citations (1)
| Title |
|---|
| J.B. PERRAUD: "Immersion in refractive index matching liquid for 2D and 3D terahertz imaging", 《2015 40TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES》, pages 978 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105044018B (en) | A kind of multi-functional THz wave imaging system and imaging method | |
| KR101702380B1 (en) | High-speed 3D imaging system using THz beam scan | |
| Mather et al. | Ultrasound tomography imaging of radiation dose distributions in polymer gel dosimeters: Preliminary study | |
| KR101712890B1 (en) | High-speed 3D imaging system using continuous-wave THz beam scan | |
| KR102109325B1 (en) | Apparatus for nondestructive and noncontact inspection of composite structures based on terahertz wave and the method for the same | |
| CN108267417B (en) | Terahertz reflection imaging system based on zero-order Bessel beam | |
| CN109444084B (en) | Terahertz wave high-sensitivity imaging device based on dual modes | |
| JPS61180129A (en) | Device for analyzing previously determined characteristic ofbody, method of testing body and device for analyzing selected characteristic of specimen | |
| CN105092705A (en) | Multi-mode signal detection method and multi-mode signal detection system for rail defects | |
| CN104188625A (en) | Multimodal microscopic imaging system | |
| KR101691544B1 (en) | High-speed 3D imaging system having non-axially symmetric lens using THz beam scan | |
| CN103389273A (en) | Photo-acoustic and optical integrated multi-mode imaging system | |
| Wang et al. | A comparative study of non-destructive evaluation of glass fiber reinforced polymer composites using terahertz, x-ray, and ultrasound imaging | |
| CN109044277A (en) | Two area's fluorescence computed tomography (SPECT) system of near-infrared | |
| CN114002160B (en) | Terahertz frequency modulation continuous wave nondestructive testing imaging system and method | |
| CN110057786B (en) | Imaging system and scanning method based on terahertz waves | |
| CN208621514U (en) | A kind of THz wave computer-aided tomography imaging device | |
| CN105699295B (en) | Utilize the quantitative detecting method and device of optoacoustic fluorescence signal ratio measurement pH value | |
| CN108458987A (en) | A kind of THz wave computer-aided tomography imaging device and method | |
| CN106681015B (en) | A kind of automatic focusing mechanism and method suitable for reflective THz wave system | |
| JPH10260136A (en) | Method and device for extracting internal information of pearl | |
| Anastasi | Investigation of fiber waviness in a thick glass composite beam using THz NDE | |
| CN210071660U (en) | Terahertz wave-based imaging system | |
| CN106773100A (en) | A kind of automatic focusing mechanism and method suitable for transmission-type THz wave system | |
| CN206223653U (en) | Water content distribution detecting device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |